1. Field of the Invention
The present invention relates to a fastener tool that can drive fasteners, such as nails and staples, into a workpiece or other structure.
2. Description of the Related Art
Known fastener tools include a body having a drive mechanism for reciprocally moving a driver. A driver guide is mounted on and extends downward from the body and has a guide channel formed therein for supporting the driver. Fasteners are serially supplied from a magazine into the driver guide by means of a fastener feeding device. The fasteners are then driven by the driver through the open lower end of the driver guide. A handle is mounted on and extends substantially horizontally from the body. A contact arm is vertically slidably mounted on the driver guide and is operably connected to a trigger that allows the operator to control the operation of the drive mechanism. The magazine has a substantially cylindrical configuration, is disposed below the handle and is connected to the rear side of the driver guide via the fastener feeding device. The magazine can store paper or wire-collated strip nails in a coiled configuration.
When the fastener tool is not being used, the operator may conveniently place the tool in an upright position on the floor or the surface of the workpiece. As a result, the driver guide is substantially vertically relative to the floor and the operator can readily grasp the handle in a substantially horizontal position to restart the driving operation. However, when placed in the upright position, the lower end of the contact arm and a rear peripheral edge of the bottom of the magazine will serve as a support leg device. The contact arm will be generally held in a position to extend downwardly from the lower end of the driver guide by the biasing force of a spring.
In order to maintain such a fastener tool in a stable upright position, Japanese Utility Model Registration No. 2,539,886 teaches a magazine having two downward protrusions on the bottom of the magazine, which protrusions are spaced laterally from each other. As a result, the two protrusions on the magazine and the lower end of the contact arm form three vertexes of a triangle and the tool center of gravity is located within the triangle when the fastener tool is in the upright position.
According to this reference, the tool can be placed on the floor or workpiece surface with improved stability. However, the lower end of the contact arm serves as one of the support legs. Thus, if the contact arm accidentally presses the floor or the workpiece surface when the tool is in this position, the contact arm could be sufficiently lifted to permit actuation of the trigger to start the drive mechanism of the driver. As a result, a nail may be inappropriately driven into the workpiece or floor. Therefore, in this design, the contact arm may not properly perform its function of preventing nails from being accidentally driven into the floor or the workpiece surface.